How to test high-energy lasers without frying satellites

Using an infrared laser pointer, the Marine JTAC marks the best landing spot for the pilots of the C-130. In the future, the Defense Department could use lasers in a very different way. (Sgt. Justin T. Updegraff/Marine Corps)

One day in the future, the Defense Department could use lasers to knock out drones and blow up incoming rockets.

It sounds like the world of science fiction, but the Army is leading the charge toward Directed Energy, or DE, with programs such as the high energy laser tactical vehicle demonstration (HEL TVD). Officials say this battlefield-ready mobile laser should reach program-of-record status within five years.

What kind of computing will be needed to support laser weapons? What new intel will these systems potentially provide? C4ISRNET talked through the implications of directed energy with Dr. Craig A. Robin, the new senior research scientist for directed energy applications at Army Space and Missile Defense Command/Army Forces Strategic Command.

Dr. Craig A. Robin is the new senior research scientist for directed energy applications at Army Space and Missile Defense Command/Army Forces Strategic Command.

C4ISRNET: Laser weapons – really? What’s the state of DE today?

ROBIN: Directed energy describes two large technology areas, one being high power microwaves, HPM, and the other being high energy laser, HEL. The most interesting area right now is high energy laser. That’s the field that is getting the most attention.

At Space and Missile Defense Command we are focused on how these can be applied to counter UAS, counter RAM [rockets, artillery and mortar], and Maneuver Short Range Air Defense, which is a mobile defensive capability.

C4ISRNET: So it’s primarily defensive at this point?

ROBIN: That is correct. We want to protect and defend fixed and semi-fixed sites or bases.

C4ISRNET: What kind of computing resources will be needed to support DE going forward?

ROBIN: For high energy lasers a lot of the computing capability already exists, which is good. The computer infrastructure is already there. So in these first steps onto the battlefield, when the HEL takes the role of a shooter, it fits within the existing command and control architecture. It enables a unique air and defense capability, but really operates within the existing battlefield architecture. We don’t want to reinvent the wheel.

C4ISRNET: How do you make that happen? How do you introduce a new capability within an existing command and control (C2) framework?

ROBIN: For example, the kill chain for a mortar engagement threat would be for some existing radar system to identify that target and communicate that information to cue the high energy laser. The laser slews to acquire that target and then a fire control system on board engages.

It’s essentially a radar system looking around and identifying possible threats, just as it would in a conventional system. We are treating the laser right now as if it were just another kinetic weapons system, right up to the point when that high energy asset engages. The only real difference, and the big advantage, is that we have a deep magazine – we don’t run out of missiles – and we have high precision targeting.

C4ISRNET: Is there any specific initiative pushing to envelop DE within existing C2 tools?

ROBIN: Not specifically. The focus in the Army is to transition to laser technology. Implicit in that is that we nee to integrate this into the current command and control scenario. There is no specific C3ISR initiative to supported directed energy but there is an overall effort to marry this technology with the existing architecture.

C4ISRNET: How will intel factor in as DE becomes a part of the arsenal?

ROBIN: One big difference with laser -- and it’s a challenge we have to continue to address -- is about laser deconfliction.

A kinetic weapon will eventually fall back to Earth if you miss. A laser will keep going on into space and possibly interact with something in orbit. Fortunately, there is an organization called the Joint Space Operation Center and within that there is a smaller organization called the Laser Clearinghouse, which is responsible for registering high energy laser tests and de-conflicting those tests with satellites orbiting the earth.

It tracks all of the objects in space and when want to do testing it informs us what the day and time window is when we can test it.

C4ISRNET: So you don’t accidentally … shoot down a satellite?

ROBIN: Basically yes, although lasers, like all lights, as subject to diffraction. As that beam propagates it diverges, it gets bigger and bigger and at some point in time the energy is spread out so widely that it becomes insignificant. It’s not quite as dire as it may sound, but it does need to be part of the calculation.

The clearinghouse can give you guidance for scheduled tests. But what happens when this goes live on the battlefield, when there isn’t that window for advance planning?

In the battlefield we obviously can’t call the Laser Clearinghouse every time we want to engage a threat. So the complexity is going to increase. Ultimately, we will need to work in real time. That effort is ongoing. It’s a matter of communication. The Laser Clearinghouse has real-time access to what is moving around the planet, and ultimately this weapons system will have to have than same access.”

C4ISRNET: In that sense, laser systems will consume ISR data. Might these weapons also be a source of new intel?

ROBIN: We think so. The nature of a high energy laser changes ISR. It’s a powerful system -- a laser sub-system and a beam control sub-system – and the beam control is basically a telescope that points the laser with an active illumination capability. That means the target illumination laser narrows the field of view to give a very fine precision track of the target.

That could be used as an ISR capability as well. You don’t have to shoot everything you track. There’s a basic idea that you would use this as a surveillance capability, another ISR data point. It may be that the high resolution of our telescope is something that will be worth exploring further as an ISR asset.

C4ISRNET: How will the rise of DE ultimately impact the soldier on the ground?

The army is using this technology to make the battlefield safer, so for the soldier the hope is that we will have a high-tech. low-cost means to enhance our current capability. We won’t really know how it will change the battlefield until we get it into the warfighter’s hands. But we know that the ability to prosecute targets at the speed of light will change the calculus.

At the very least we know the people on the ground will have to wear laser goggles.